Anger is a necessary condition for political change. But, by itself, it is not a necessary and sufficient condition for change. Tea Party folks - who are not really much more than angry Republicans - are angry. So what?
Anger won't change the country. There has to be a legitimate plan/option to get behind for political change to happen. People don't want to vote for "the angry candidate who likes to bitch and moan." They need to understand what the plan is.
This is why the Tea Party movement is stock in neutral.
The Tea Party Express multi-city tour that Palin put her name and fame to was nothing more than a Republican scam to make some money. It just suckered a bunch of ignorant Tea Partiers into forking over their SS and welfare checks to pay for Sarah Palin's appearances. They never actually built an agenda.
Now, the other thing that is going to prevent the Tea Party anger from spreading is that the nation's economy is rapidly improving. Job creation is now taking place, GDP is rising at a brisk pace, and even real estate is showing signs of significant improvement. President Obama has accomplished HC reform and gotten most of the world's nuclear powers to agree to secure loose nukes. The Iraq war is winding down. We will have financial regulatory reform on Wall Street and possibly even a climate bill.
Immigration reform debate will likely be a political win for Democrats as they secure the growing Hispanic vote for the next 2 decades, and the Supreme Court nominee could really stir the base.
It is already a tiny, and largely inconsequential movement, but next year, there won't be a Tea Party movement at all.